Rotary internal combustion engine



Oct. 13,'1942.- -A. M. BRIGGS ROTARY INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 1 Filed Oct. 8, 1941 Oct. 13, 1942. A. M. BRIGGS ROTARY INTERNAL COMBUSTION ENGINE Filed Oct; 8, 1941 2 Sheets-Sheet 2 Patented Oct. 1 3, 1942 UNETED STATES PATENT OFFICE ROTARY INTERNAL "COMBUSTION ENGINE Arthur M. Briggs, Huntington Park, Calif. Application October 8, 1941,;SerialNo. 414,085

2 Claims. (or. 123-1 6.)

The invention herein described relates to internal combustion engines, and more particularly to those of the rotary type in which the capacity of rotating chambers is changed by their constantly varying cross-sectional area.

Heretofore engines of this type have been characterized by a multiplicity of compartments and auxiliary moving parts. One object of the present invention is to simplify the construction and reduce the number of parts to a minimum.

Another object of the invention is to make it possible to have the intake and exhaust ports closer together than the blades without employing any special auxiliary moving part to prevent intercommunication therebetween.

Another object is the provision of means whereby the incoming carbureted gasoline is heated by passing through the rotating parts of the motor itself, and whereby the motor is cooled by such initially unheated mixtures passing therethrough.

Another object is the reduction of unbalanced reciprocation to a minimum.

Another object is the complete elimination of valves.

.Another object is to achieve a construction that will give great power with a minimum of weight.

Another object is the elimination of the conventional oiling system.

An additional object is the attainment of a high compression ratio.

A further object is the provision of a blade construction that permits the replacement of the par-ts most subject to wear.

Still another object is the prevention of abrupt changes in the radial velocity of the blades.

Yet additional objects will appear as the specification proceeds.

In the drawings:

Fig. 1 is an elevation, partly in section, of my improved engine, showing its construction, and, diagrammatically, the cycle of operations.

Fig. 2, on the second page of the drawings, is a longitudinal section taken substantially on line '2-2 of Fig. 1.

Fig. 3 is an elevation with the front end plate in place, showing the cam and rotor shaft hearing in broken lines.

Fig. 4, on page 1 of the drawings, is a perspective View of the front end plate, showing the construction of the scroll, or internal cam.

Fig. 5 is an elevation, partly in section, of one of the blades.

Fig. 6 is a bottom View of the blade of Fig. 5.

Fig. 7 is an exploded perspective view of a blade of modified-construction in which the wiping edge is replaceable.

In the following description of my invention, the salient structural features are stressed, and comparatively few details are given regarding such matters as the external shape, the position of cooling fins, the method of anchorage, etc., as each designer will wish to specify these items according to individual preference or the particular requirements of a given adaptation.

The embodiment of my invention hereinafter described does not require the conventional oiling system. The oil is mixed with the gasoline; and asthecarbureted mixture is passed through the engine to cool the engineand to heat the mixture, the -oil contained in the mixture serves to lubricate all the moving parts.

The preferred embodiment of my invention comprises three main castings-a body or casing A, a front-end plate B, and a rotor C. The back end plate Dis preferably cast integrally with the body. 7

"The rotor C is provided with a plurality of radial recesses E, preferably four in number, extending parallel to the-shaft F to which the rotor is keyed by key member G. Holes 5 in the rotor conserve material, reduce the mass, and provide channelsin which the :carbureted gas is heated in a manner hereinafter explained.

The shaft F is mounted in the end plates by means of ball bearings H, Fig. .2, each end plate having a bore J for the shaft and a counter-bore K for the bearing, asshown in Figs. 2 and 4.

Each recess E carries a blade L slidably mounted therein. Grooves Q in the sides of the blades assist in the distribution of the oil and also help to collect any-carbon that may form, and the holes 6 in the bottom of the blades serve to reduce the weight of the rotating and reciprocating parts.

The :ends of these .blades are each provided with a pin M surrounded by a bushing N. These bushings travel in internal cam slots or scrolls O in the end plates B and D.

As clearly shown in Fig. 1, the main bore of the body or casing is of non-circular cross-section, the contour being somewhat elliptical. .More particularly, this contour, in the illustrated embodiment, comprises a portion I having a radius one or two thousandths greater than that of the rotor, a diametrically opposite and longer portion 2 having a radius approximately three thirty-seconds of an inch greater than that of portion 1, two long portions 3 and 4 each of aradius approximately one inch greater than that .ofportion I, and four portions, each occupying' an angular space of 30 degrees, that join these other portions in such fashion as to impart simple harmonic motion to the radially moving blades as they contact these surfaces of the bore during the rotation of the rotor.

The periphery of the rotor and the contour of the main bore of the casing divide the intervening space into three main sections-a wide channel S bordered by the portion 3, a narrow channel T bordered by the portion 2, and another wide channel U bordered by the portion 4.

The center line of each of the cams of scrolls in the end plates is everywhere the same distance from the corresponding inside wall of the casing, measured along radii extending from the center of the bore for the shaft. The sides of the scroll must therefore be envelopes of a family of circles sufficiently larger than the bearingsN/to provide an operating fit.

The scrolls are cut from the inside surface of the end plates and extend to an annular cored space P.

The front end plate B is attached to the body or casing A by means of bolts 1.

A spark plug R is threadedly mounted in a hole in the side wall of the casing to fire into the channel U at the end thereof that is opposite from the exhaust port V.

A port Y, Fig. 2, opens into the cored space P from a flange X, to which is attached a pipe Z that introduces the carbureted gasoline and a small mixture of oil from a carburetor-not shown in the drawings because it forms no part of the present invention. The carbureted gasoline and oil then pass through the cam slot and into the grooves Q in the sides of the blades L and also into the large holes 5 in the rotor, but not into the channels S, T and U, because the maximum over-all diameter of the cam opening is less than that of the rotor. From the openings in the blades and rotor, the mixture next passes into the cam slot 0 in the front end plate B, then into the cored space P in the front end plate, and aft-er being heated in these various passageways it finally leavesthe end plate B through port 8 and is drawn through pipe 9 into the intake port W, Figure 1.

As the rotor turns in the clockwise direction indicated by the arrows in Fig. 1, the movement of the particular blade L that is entering channel S causes the heated mixture from intake port W to be drawn into the space H! behind the blade. When the following blade has passed port W, the space between the leading and the following blade will be filled with the carbureted mixture at a pressure slightly below that of the atmosphere. The leading blade then recedes into its recess in the rotor under action of the cam and the shortening radius of the bore, and moves across the portion 2; and the following blade con currentl compresses the charge from the wide channel S into the much narrower channel T.

When the following blade has passed into the channel T, the leading blade will have passed into channel U to a position just beyond the spark plug R where its tip will be in engagement with portion 4 of the inner wall of the casing. This is the position in which the spark plug ignites the compressed gas. As the leading blade in this position exposes a much greater area to the pressure of the expanding gas than does the following blade, the entire rotating structure is driven in the direction of the arrows. When the following blade reaches the firing position, the leading blade will have passed far enough across the exhaust port P to open it, and the further movement of the following blade forces the exploded gases through the open exhaust port.

When the blade that we have referred to as the leading blade has continued past the portion I that engages the rotor and seals the exhaust and intake ports against each other, and has also passed the intake port W, one complete cycle of operations will have been completed for this blade, and it will begin again to suck heated, carbureted gasoline into the space I0 for a repetition of the cycle of operations just described. Meanwhile, however, each of the other blades will have performed in a like manner. It will thus be clear that there is an intake, compression, power and exhaust operation associated with each blade during one revolution of the rotor, and that there are consequently four power strokes per revolution.

After a given blade has passed just beyond the intake port, thus sealing it from the portion S ahead of the blade, the first degrees of its cycle of rotation draws in the complete charge of mixture, which then occupies the chamber S, bounded by the 90 degree uniform-radius arc 3. The compression then begins, and after the blade has moved through an additional angle of 90 degrees, the charge behind it reaches its maximum compression. The next 30 degrees of angular movement effects no increase or decrease of the compression, but moves the charge ahead until the following blade reaches the extreme rear end of the channel T, at which time the point of the leading blade is at the beginning of the constantradius arc 4. The spark then takes place, and the expanding gases exert their pressure on the blade and drive it through an arc of 75 degrees.

The blade then slips beyond the edge of the exhaust port, and the exploded gases behind the blade are then driven through the port during the next '75 degrees of rotation, which corresponds to the power stroke of the following blade. During the 75 degrees of rotation in which these gases are being exhausted, the blade of reference moves through the 30 degree angle adjoining the exhaust port, the 15 degree angle occupied by the arc l, and the final 30 degree angle adjoining the intake port, which completes the 360 degree cycle of rotation.

The second 90 degrees of this cycle of rotation compresses the gas 4.84 times, if the minimum and maximum radii of the bore in the casing are 4 inches and 5 inches respectively, and the other dimensions are in accordance with the foregoing description. This raises the pressure to about pounds to the square inch and the temperature to about 980 degrees absolute.

The contour of the irregular portions of the bore in the casing and of the corresponding portions of the cams, is calculated to give a simple harmonic radial motion to the blades, thus reducing vibration to a minimum. It will also be observed that opposite blades recede into their recesses or move out of them at substantially the same time, a design feature that serves to balance the reciprocation.

Inasmuch as the blades each move from their innermost to their outermost positions while rotating through an arc of 30 degrees, and completely recede while moving through an equal angle, it follows that the period of the simple harmonic motion of the blades is equal to 60 degrees 0f rotation, and that the angular velocity of a point on the auxiliary circle of the S H. M. is six times the angular velocity of the rotor.

Fig. '7 illustrates a modified blade structure in which the edge that contacts the bore is removable and replaceable, so that a new edge may be supplied in the event that excessive wear should prevent a perfect sealing contact between the blades and the undulating contour of the bore.

Although I prefer that the casing and the back end plate be cast in one piece, my invention contemplates that they may be cast separatelyin which case the main body will be open at both ends. The back end plate is then designed as a mate to the front end plate, and it is attached to the main body in the same manner.

Various other modifications, additions, omissions and substitutions may be made from the embodiments herein described without departing from the broad spirit of my invention as defined in the appended claims.

My claims are:

1. A rotary internal combustion engine comprising a casing with an opening therein of substantially elliptical cross-section; end plates closing said opening; a circular rotor mounted in said plates and disposed in said opening intermediate the longest diameter thereof, the periphery of said rotor substantially engaging a side wall of said opening; said rotor and the side walls of said casing serving to define a relatively narrow channel therebetween located substantially diametrically opposite the engaging portions of said rotor'and wall, and two relatively wide channels located substantially diametrically opposite each other and each disposed between said engaging portions and said narrow channel; an intake port opening into one of said wide channels; an exhaust port opening from the other wide channel; a spark plug positioned to fire into said last-mentioned channel; radial recesses in said rotor; blades slidably disposed in said recesses and each carrying a pin on each end; an annular cored space in each end plate; a cam slot in each plate extending from said opening to said space, said slot constructed and arranged to receive said pins and keep the outer edges of said blades by means of said pins in constant slidable engagement with the side walls of said casing during rotation of the rotor; a first passageway for conducting unheated oil and carbureted gasoline into one of said cored spaces; and a second passageway for conducting heated oil and carbureted gasoline from the other cored space to said intake port.

2. A rotary internal combustion engine comprising a circular rotor having a plurality of radial recesses extending parallel to the axis of rotation of said rotor; blades each slidably mounted in one of said recesses; an annular casing wall surrounding said rotor and blades and defining with the periphery of said rotor a plurality of communicating channels at least one of which has a width that is different from that of the others; an intake port opening into one of said channels; end plates for said annular wall each having a cored annular space therein and a cam slot extending from the inner surface of the plate to said annular space; a pin on each end of each blade protruding into the cam slot of the adjacent end plate; the contour of said cam slots and annular wall constructed and arranged to give said blades a simple harmonic motion in said recesses as said blades pass from a channel of one width to a channel of a different width; a first passageway for conducting unheated oil and carbureted gasoline into one of said cored spaces; and a second passageway for conducting heated oil and heated carbureted gasoline from the other cored space to said intake port.

ARTHUR M. BRIGGS. 

